<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="jquery.3.4.1.js"></script>
</head>
<body>
    <button>点击事件</button>
</body>
<script>
    $('button').click(
        function () {
            // var btn = $(this).clone()
            var btn = $(this).clone(true)
            $(this).after(btn)
        }
    )
</script>
</html>